The United States has the sixth largest Hispanic population in the World (15 million in March 1983). Among Hispanics the population of Mexican origin is by far the largest group (59.4%) with a growth of 93% from 1970 to 1980. However, until recently policy makers have had difficulty in finding accurate and reliable information about the characteristics, health needs and utilization patterns of health services of this group. A major gap is the lack of knowledge about the Mexican-American Children's needs for health care. This subgroup had the lowest physicians contacts when compared with other children (about 3 visits per child per year). In 1982, the Department of Health and Human Services initiated a Hispanic Health and Nutrition Examnation Survey (HHANES). This investigation will use data generated by this HHANES to examine the health needs and levels of utilization for these needs using both "medically defined need" (by medical examiner) and self-reported need. Selected socioeconomic, demographic and cultural factors will be assessed in order to determine their impact in the utilization rates of health care among this group. The specific objectives include: 1) to assess by medical examination and self-reported procedures the health status of Mexican-American children including selected chronic diseases, acute conditions and risk factors, 2) to ascertain the extent in which physicians and other health are personnel were contacted when illness or injury was experienced by Mexican-American children, 3) to ascertain the extent to which physicians and other health care personnel were contacted for routine preventive care as recommended by the American Academy of Pediatrics guidelines, 4) to evaluate differences in utilization of health care among Mexican-American families with different level of acculturation (measured by location of birth, language spoken and place of education), 5) to assess the relative importance that selected socioeconomic, demographic and health status characteristics have in the pattern of health care utilization among Mexican-American children, and 6) to identify in this group the degree of agreement between self-reported and medically evaluated health needs. Four major target chronic diseases, six health status indicators, four indicators of utilization and eight indicators of utilization in relation to need will be used in evaluating the health care needs of this group. By identifying the health needs and the factors associated with unmet needs, recommendations may emerge for targetting programs and policies to effectivelys serve the ever-increasing health needs of the Mexican-American children.